Abstract: 【Objective】 This study aims to examine the effects of application time of Flumetralin and Mepiquat chloride on plant type and economic characters of cotton, In order to screen out the optimal time for chemical capping and pre-regulation and shaping of cotton. 【Methods】 The split-plot experiment design was carried out in this experiment to determine the plant height, leaf branch length, fruit branch length, internode length, boll number, boll weight, single boll weight, yield and fiber quality index of cotton capping period as the main plot, cotton with different time before capping as secondary zone and artificial topping as control. 【Results】 Flumetralin and Mepiquat chloride were administered twice in cotton field for cotton regulation and capping. The plant height and leaf branch growth of cotton chemical capping were lower than those of artificial topping. The longer the two-period application period of plant growth regulators mixed with Flumetralin and Mepiquat chloride, the shorter the cotton plant height growth. The distance between main stem nodes of cotton inverted one, inverted two, and inverted three was significantly shorter than that of the control (P <0.05), and the length of the fruit branches of inverted one, inverted two, and inverted three was 61.57% -70.57% shorter than the control. The number of cotton bolls in different parts of cotton was as follows: lower boll > middle boll > top boll, and it was mainly concentrated in the lower part of cotton. With the shortening of the interval between the two treatments, the number of bolls per plant and the weight of single boll increased, while the single boll weight of cotton capped on July 15 decreased, but there were no significant difference between each treatment and control (CK0-5, CK0-10, CK0-15)(P>0.05). 【Conclusion】 The interval of two applications also had certain influence on cotton fiber quality index. According to weight of seed and lint yield of cotton, the plant growth regulators mixed with Flumetralin and Mepiquat chloride sprayed twice on June 30th and July 10th can cause cotton to cap itself and help the formation of higher light efficiency groups.

Key words: cotton; flumetralin; mepiquat chloride; application time; plant type; economic characters

摘要： 【目的】研究氟节胺与缩节胺施用时间对棉花株型及其经济性状的影响,筛选出棉花化学封顶和前期调控塑形最佳时间。【方法】采用裂区试验设计,以棉花不同时间封顶施药为主区,封顶前不同时间施药调控为副区,人工打顶为对照,测定棉花株高、叶枝长、果枝长、节间长、结铃数、单铃重、实收产量以及纤维品质指标。【结果】棉田施用2次氟节胺与缩节胺进行棉花调控和封顶。棉花株高和叶枝增长量均低于人工打顶,并且2次施药间隔期越长则棉花株高增长量越少,倒1、倒2、倒3主茎节间距显著短于对照(P＜0.05),棉花倒1、倒2、倒3、倒4果枝长度较对照缩短61.57%~70.57%。棉花不同部位结铃数表现为下部铃＞中部铃＞上部铃,且主要集中于棉花下部。随着2次施药间隔期缩短,棉花单株铃数、单铃重有增加趋势,而7月15日封顶棉花的单铃重呈减少趋势,但与对照(CK0-5、CK0-10、CK0-15)无差异(P＞0.05)。【结论】2次施药间隔期对棉花纤维品质指标也有一定影响。在6月30日和7月10日2次施药可以达到棉花化学封顶效果,有助于高光效群体形成。

关键词: 棉花, 氟节胺, 缩节胺, 施用时间, 株型, 经济性状